Does this mean the tide is turning and vaping is starting to decline?

“These trends suggest that some individuals are trying but not continuing use of e-cigarettes, but further investigation with individual longitudinal on use of both e-cigarettes and other nicotine products is needed,” they wrote.

Media captionSingapore bans vaping to ‘protect its youth’

And not all of the survey respondents were vaping less.

Vaping increased significantly among those who had never smoked, the authors report – concerning because “these never smokers were being exposed to nicotine and other harmful ingredients”.

And that’s also the worry about usage among school-age minors?

Exactly.

The US Food and Drug Administration acknowledges that vaping has become “wildly popular with kids” and has recently launched a crackdown on outlets which illegally supply the underage, with a focus in particular on the fashionable Juul devices.

Some have even raised worries that many schoolchildren don’t understand that Juuls – which come in flavours including mint, fruit medley and crème brûlée – are e-cigarettes and contain nicotine, so may not answer survey questions correctly.